Geoege e



(No Model.)

G. R. FULLER. JOINT FOR ARTIFIGIALLIMBS.

'N0.370,7'74. Patented 0011.4,1887.

N. PETERS, Pholo-Lilhngnpherv Wanhinghm D C.

UNITED STATES PATENT OFFICE.

GEoRGE R. FULLER, or ROCHESTER, NEW YORK.

JOINT FOR ARTIFICIAL LIMBS.

SPECIFICATION forming part of Letters Patent No. 370,774, dated October4, 1887.

Application filed March 26, 1887.

To aZZ whom, it may concern:

Be it known that I, GEORGE B. FULLER, of Rochester, in the county ofMonroe and State of New York, have invented a new and useful Improvementin Joints for Artificial Limbs, which improvement isfully set forth inthe following specification, and shown in the accompanying drawing.

The object of my invention is to produce an improved wrist-joint for anartificial hand, the same being hereinafter fully described, and

p more particularly pointed out in the claim.

Referring to the drawing, the figure shows a view taken of the inside ofa right hand and a portion of the arm, the latter with the wristjointand a portion of the hand being centrally longitudinally sectioned,thehand being shown in three positions by full and dotted lines.

Ijoin the hand A to the arm B by a balland-socketjoint, 0, similar insome respects to those heretofore used, by means of which the hand has auniversal movement upon the arm, the joint allowing also a twisting orrolling of the hand upon its axis; The ball a of the jointis made rigidwith or a part of the hand, and fitted to turn inaspherical socket, 12,formed in the end of the arm. An axial eyebolt, c, is caused to passlongitudinally through the timber h at the end of the arm, and through aspring cross bar, d, within the arm at right angles with the bolt. Thebolt is threaded and provided with a washer, e, and set-nutsff on theoutside of the spring-bar. A space, 9, is left between the spring-barand the part h for the purpose of lightness and to give the bar anopportunity to spring or yield at its center in a line correspondingwith the axis of the bolt.

The ball is formed with a hemispherical concentric cavity, 1', and astrong internal bar, k, through which a short eyebolt, Z, passes, thesame being held by a nut, n, on the outside of the bar. The heads or eyeportions of the bolts 0 andl lock, as shown, the axes of the two boltsforming a straight line when the wristjoint is not deflected. The barkis formed Serial No. 232,458. (No model.)

with an internal concentric cavity, 0, in which to receive the head ofthe bolt Z. The parts being in place are drawn together by tighteningthe nuts ff. The point of contact or bearing-pointp between the twobolts at their eyes is exactly at the center of the ball or sphere, sothat the longitudinal strain or pull upon the bolts remains constantwhile the hand is moved to any position relative to the arm the boltsalways occupying positions radial to the sphere. A circular radialopening, 1', is formed in the hemispherical shells of the ball aroundthe bolt 0, so that said bolt where it passes through said shell shallnot interfere with the turning of the ball in the socket. This openingalso serves as a space through which to allow the short eyebolt to bepassed to its place within the ball.

Set-nuts like those shown at ff may be provided for thefeyebolt Z,instead of the single nut n, if found desirable, and a yielding orspring washer may be placed between them and the bar It, and a similarspring-washer may be substituted for the washer a, should these be foundto add a desirable elasticity to the joint.

One or the other or both of the tie-bolts c and Z are, fitted so as toturn in their bearings in the hand and arm, so that the hand may berolled or turned upon its axis when occupying any position relative tothe arm.

What I claim as my invention is An artificial hand formed with aspherical GEo.v FULLER.

Witnesses:

E. B. WHITMoRE, M. L. MODERMOTT.

